Manometer



Decl- 1932- 'r. R. HARRISON MANOMETER Original Filed Aug. 10, 1926 INVEVTOR T W i /W ATTORNEY Patented Dec. 13, 1932 T UNITED srAras PATENT OFFICE THOMASER. HARRISON, .OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOB TO THE BROWN INSTRUMENT COMPANY, OF PHILADELPHIA, PENNSYLVANIA, A CORPORATION OI PENNSYLVANIA I Original application filed August 10,1926, Serial lio. 128,466. Divided and this application 10 1927. Serial No. 218,688.

The general object of the present invention is to provide a manometer characterized by its mechanical sim licity, rugged character and durability, an by-the comparative ease with which it canbe constructed with the pre; cision necessary for its use as a part of a ow meter, though certain features of the invention are not restricted to'use in a flow mete manometer. More specifically, the object of the invention is to improve the construction and operation of, and to avoid corrosion troubles in a" manometer of the type in which pressure or liquid level changeswithin", the manomter actuate an exhibitingginstrument external'to the manometer through the inductive inter-action of an external winding or windings and a. magnetic body located within the manometer and moving in response to said changes.

The variou features of novelty which characterize li ly invention. are pointed out with articularity in the claims annexed to and ormi g, a part of this specification. For a bette ri understanding of the invention,

however, its advantages and specific objects attained with its use, reference should be bird to the accompanying drawing and descriptive matter in w ich I. have illustrated and described preferred embodiments of my invention.

Of the drawing: v Fig. 1 is ,a sectio aLeIevation taken on the line 11 of Fig.

Fig. 2 isa p n vi Fig; 3 is an elevation of a portion of the apparatus shown, in Fig. 1 in section on the line 3 3 of Fig.1; and

Fig. 4 is a diagrammatic elevation of alternately usable manometer range.

,The manometer shown in the drawing ,cbmprises a housing or body comprising up.- per and'lower chambered parts A and A, respectively, which may be formed of cast iron and are accurately fitted and secured together by suitable dowel pins and bolts. The lower housing body AQ- is formed with a chamber D for a float C i hich rests upon the mercury or other manometer sealing liquid.

uinomnrnn ew "with parts brokenv awav and 1n se tion;

parts employed to change the Y illed September lower end of the cham er I5 terminates at its other end in a vertical enlargement or socket E which opens at its upper end into a chamber G comprising an enlar (1 lower portion -A channel E openin at one end into the v formed in the part A, an a smaller upper I whichhcontrols communication between the passage H and H24 The lower (if the two pressures to be impressed upon the sealing liquid in the manometer isf'transmitted to the chamber G through a pipe L shown as threaded into aplug closing the upper end of the chamber. The higher pressure is transmitted,

to the iipper end of the chamber .D through an passages K and K formed in 5 a pip the body pan A.

With the manometer construction described, the differential between the ressures transmitted to the upper ends'ef t e chamhers D and G by the pipes K and L, respectively, will cause a corresponding displacement between the sealin liquid levels in the manometer leg formed y the chamber D,

and in the second manometer leg which is' formed by the member F when the valve I is closed, and is formed by the member F and the space in the chamber G surroundingthe latter when the valve I is open. The change in sealing liquid level in the chamber D pro- "duced by a given pressure 'difi'erential depends upon the relative horizontal cross section of the two manometer le s, and will be much a greater, for example, w en the valve I is open,

than when thelatter is closed. The constant or range of the manometer may be also varied in definite steps by the interchangeable use of one or another of a series of standpipe members F of different predetermined internal diameter such as those shown in Fig. 4. In order that the range of the "manometer with the valve/Iopen may be the same, regard 100 5 means, of coursei that the lower portions of a closing the valve I, so that the same amount larger member must have a thinner wall than a art of smaller diameter. In practice the sea ing liquid should be brought to the same level in the chambers D and G before of sealing liquid will always be trapped in the portion of the chamber G surroundin the part F in place when the valve I is cl Various arrangements may be employed for measuring, or transmitting to an indicator or regulator the changes in sealin liquid level occurrin in the chamber D. 'l he particular means s own for this purpose comprise a magnetic body or core 0 carried at the u per end of a non-magnetic stem portion 0 the float C, and vertically movable within a pair of surrounding end to end coils P and P so that the inductances of the two coils are relatively varied b the movement of the core 0 as the float rises and falls. The coils P and P, are mounted on, and the core Oismovably received in an extension of the chamber C formed by a tubular part B threaded at its lower end into an opening in the portion of the part A which closes the upper end of the chamber D. As shown, the coils P and P and a terminal board P through which the necessary connections to the coils are made, are enclosed in a casing Q, of inverted cup-shape which is apertured for the gassa e of the u per end of the tubular part an is normal y anchored in place against the housing body part A by a nut Q, threaded onto the upfir end of the part B. A s ring R interposed tween the upper end 0 the coil P and at the top of the casing Q normally holds coils P and P snugly in place. In practice I prefer to connect the coils P and P into an impedance bridge of the type disclosed and claimed in my application Serial No. 106,346, filed May 3, 1926, as a division of my earlier application Serial No. 78,148, filed December 29, 1925, by which a core forming the actuatin element of an indicator or recorder is caused to move in correspondence with the movements of the core 0, but as such impedance bridge forms no part of the resent invention, its illustration or further escription herein is unnecessary.

In some uses of the manometer the upper portions of the manometer le above the sealing liquid are normally fille with water. For example, when the manometer is used as a part of a steam flow meter the upper portions of the legs fill with water of condensation. In such cases to prevent oxidation of the core 0 which otherwise would be in contact with water, the space in the tubular part B not occupied by the core 0 and float stem may advantageously be filled with a tween the chambers D and G suitable oil which floats on the body of floating on the sealin liquid and mte between the latter an the oil. For an other substanoe'heavier than water. With the manometer thus filled with different liquids as the impressed pressure difierential varies and the sealing liquid is correspondingly disglaoedci water flows into or out of the chamber into and out of the chamber G without disturbing the body of oil in the tube B. For its intended use the tubular part B should be made of non-corrosive nonmagnetic material of high electrical resistance which preferably is an alloy consisting of approximately nickel and 20% chromium. That alloy possesses high tensile strength and thus permits the tube B to be made with a relatively thin wall as shown, even when the manometer is to be used with extremely high internal pressures. The fact that the tube is made of non-corrodible material permits of the close fitting of the armature O in the tube illustrated in the drawing, without risk of having the armature movements interfered with by the corrosion of the inner wall of the tube. The closeness of the armature fit in the tube and the thin wall of the latter are es ially desirable, because each permit of a re notion in the distance between the core 0 and the surrounding windings and such reduction improves the electromagnetic interaction between the core and the coils and contributes to the desired accuracly and sensitiveness of the a paratus.

he closure of the upper en of the part B by the removable plu B facilitates the initial char ometer. T e initial calibration and .recalibrations, when necessary, of the manometer are also facilitated by the communication berovided for through the channels M and when the normally closed valve M see Fig. 3) is opened. When the valve is opened the pressures in the upper ends of the two legs of the manometer equalize, so that the same sealing li uid level can then be secured in each leg 0 the manometer.

Advantageously, the manometer body is made of cast iron or analo one material to insure the necessary strengt and cheapness of construction. To minimize corrosion and to practically eliminate fouling resultin from corrosion, otherwise experienced with iron manometers internally exposed to contact with water, steam, corrosive gas, or the like, the float chamber G may advantageously be rovided with a linin S of some material which will not be objectionably corroded by the fluids admitted to the chamber C. The lining ma be made cheaply and accurately of mold bakelite, or it ma be made of a welded tube formed from a s eet of non-corrosive metal such as the alloy consisting of use. the sealing liquid must be mercury or some and cali ration of the manmay well be provided with a linin um. The float C also should be made of a.

suitable non-corrosive material. In some cases the enlarged portion of the chamber gr formed of the same material as the linmg S,

- and the parts F may also be formed of such non-corrosive material in some cases. The avoldance of corroslon is less 1mportant,however, in the case of the chamber G and of the parts F, than in the. case of the float chamber, where the foulin which results from-corrosion may result in frictional resistance to the float movement. Furthermore, the use of the lining SA is ordinarily made relatively unimportant by the fact that the wall of the chamber G may be unfinished construction, very little clearance between the float C and the vertical wall of the float chamber D is required. 'This reduces the amount of sealing liquid required, and also reduces the tendency of the float to tip and thereby produce frictional enga mentof the core 0 with the tubular part The adjustable range manometer disclosed herein is of special utility-for use in carrying out the invention in metering disclosed and claimed in my prior application, Serial No. 126,562, filed on or about August 2, 1926. For such use the different standpipes F should be so proportioned inauniform relative which may be defined as req'uiringthat the logarithm of the number representing the diameter of any one of the standpipes differs from a the logarithm of the number representing the diameter of the next larger or next smaller standpipe by a fractional number of which the numerator is two, and the denominator is more than one.

Certain novel features of construction and arrangement shown but not claimed herein are claimed in my prior application Serial No. 128,466, filed August 10, 1926, of which this application is a division.

I While in accordance with the provisions of the statutes, I have illustrated and described the best form of embodiment of my invention now known to me, it will be apparent to those skilled in the art that changes may be made in the form of the apparatus disclosed Without departing from the spirit of my invention as set forth in the appended claims and that in some cases certain features of my invention may be used to advantage without a corresponding use of other features.

aving now described my invention, what I claim as new and desire to secure by Letters Patent, is:

1. A manometer'having chambers interconnected by a passage and arranged to receive a liquid, the level of which is variable in response to variations in the pressure to be measured, a float riding on the liquid in one of said chambers,.a magnetic armature connected to said .float for movement thereby, a tube connected to the float containing chamber and closing said chamber to the atmosphere, an inductance'coil positioned exteriorly of said tube for accurately res onding to the motion of the armature, sai armature being arranged in said tube for movement in the electromagnetic field of said inductance coil, said tube being relatively thin walled and said inductance coil and armature being arranged closely thereto whereby the electromagnetic coupling between the inductance coil and armature is close, said tube being made of a metallic steel-like alloy having non-corrodible properties and of high tensile strength, non-magnetic and of high resistivity. i

2. A manometer having chambers interconnected by a passage and arranged to receive a liquid the level of'which is variable in response to variations in the pressure to be measured, a float riding on the liquid in one of said chambers a magnetic armature connected to said float for movement thereby, a tube connected to the float containing chamber and closing said chamber to the atmosphere, an inductance coil positioned exteriorly of said tube for accurately responding to the mot-ion of the armature, said armature being arranged in said tube for movement in the electromagnetic field of said inductance coil, said tube being relatively thin walled and said inductance coil and armature being arranged closely thereto whereby the electromagnetic coupling between the inductance coil and armature is close, said, tube being made of a non-corrodible metallic steel-like alloy of high tensile strength, non-magnetic and of high electrical resistivity, said tube being accessible at its end distant from its connection to the chamber and a removable plug in said accessible end. I

3. A manometer having chambers interconnected by a passage and arranged to receive a liquid the level of which is variable in response to variations in the pressure to be measured a float riding on the liquid in one of said chambers, a magnetic armature connected to said float for movement thereby, a tube connected to the float containing chamber and closing said chamber to the atmosphere, an inductance coil positioned exteriorly of said tube for accurately responding to the motion of the armature, said armature bein arranged in said tube for movement in the e ectromagnetic field of said inductance coil, said tube being relatively thin walled and said inductance coil and armature being arranged cloself thereto whereby the electroma etic coup ing between the inductance mi and armature is close, said tube being made of a non-corrodible metallic alloy conlocated" within said tube and connected to taining substantial amounts of nickel and chromium of high tensile strength, non-mag- .netic and of high electrical resistivity;

4. A manometer casing having c ambers interconnected b a passa and arranged to receive a liquid in response to variations in the pressure to be measured and including a vertical tube opening at its lower end to the upper end of one upper. end of said tube, said mem r being ll formed with an abutment surface at its underside, and a spring extendin between one of said abutment surfaces an the adjacent end of said winding.

5. A manometer casing having chambers inter-connected by a passa e and a to receive a liquid the level 0 which is variable in response to the variations in the ressure to be measured and includin a vertical tube closed at its ufiper end an o ing at its lower end to t e u per end 0 one of said chambers, a float ri mg on the liquid in the last mentioned chamber, a magnetic armature said float for movement thereby a winding surrounding said tube and in inductive relation with said armature, a su plemental casing surrounding said win ing, means in threaded'enga ment with the upper end of said tube for etachably clamgwing said supplemental casing against the rst mentioned casing, said means also comprising an abutment surface at its underside and surrounding said tube, said first mentioned casing being formed with an o posing abutment surface surrounding the ower end of said tube, and a helical s ring surrounding said tube and compressed between one of said abutment surfaces and one end of said winding, the other end of said winding being in engagement with the other abutment surface.

A manometer casing for chambers inter-connected by a assage and arranged to receive a liquid the evel of which is variable .in response to the variations in the ressure to be measured and includin a vertlcal tube opening at its lower end to t e upper end. of

e level 0 which is variable 1,se1,1se

one of said chambers, a float riding on the liquid in the last mentioned chamber, a ma etlc armature located within said tube an connected to said float for movement thereby, a tubular winding surroundi said: tube and in inductive relation with sai armature, and means for snugly holding said'winding in place comprising an abutment surface at the ower end of said tube, and a member normally ad'acent the'upper end of, and adj ustable axia y of, and separable from said tube, and formed with an abutment surface between which and the flrst mentioned abutment surface said winding is held.

7. A manometer casing having chambers interconnected b a p and arranged to receive a liquid e level 0 which is variable in response to variations in the premure .to be measured and including a vertical tube closed at its upper end and opening at its lower end to the upper end of one of said chambers, a float riding on the liquid in the last mentioned chamber, a m etic armature located within said tube an connected to said float for movement thereby, a winding surroundin said tube and in inductive relation with sai armature a supplementalcasing surround' id win secured to the first rlnention d c an m engagement at its ower en :1 latter, and means for snugly holding said winding 1n lace comprisin an abut- 33 d1 a d b.

aspringsurroun 'ng i tu andin end to end relation with said winding, said rin and winding bein clamped between e lower end 0 said tube said tment surface an said supplemental Signed at Philadelphia" in the county of Philadelphia, and State oflewlvania, this 7th day of Se mber, A. D. 1

OMAS B. HARRISON. 

